Boring machine



P/y 5? 93@ 1 M. LUNDELL ET AL 29939;?2@

BORING MACHINE Filed Dec. 14, 1933 2 Sheets-Sheet l May 5? i936., J. MLUNDELL Er AL 2?@39972@ BORING MACHINE Fi'led Dec- 14, 1935 2 Sheets-Sheet 2 Patented May 5, 1936 1 UNITED STATES PATENT OFFICE BORING MACHINE nesota Application December 14, 1933, Serial No. 702,297

9 Claims.

Our invention relates to a boring machine and more particularly to a boring machine for reestablishing, reboring and refinishing bores in an internal combustion engine cylinder block, of accurate size and alignment.

The object of the invention is the provision of a portable self-contained motor-operated boring machine that is highly eiilcient and of compact form which permits the same to be mounted on the engine block of an internal combustion engine without removing said block from the chassis of an automotive vehicle and where it is necessary to work close to the cowl or other parts of the vehicle.

To the above end, generally stated, the invention consists of the novel devices and combinations of devices hereinafter described and defined in the claims.

In the accompanying drawings, which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. 1 is a fragmentary view partly in side elevation and partly in section showing the cylinder block of an internal combustion engine on which the improved boring machine is mounted with its cutter head in one of the bores of said block;

Fig. 2 is a plan View of the feed bar housing head with its cover plate removed to expose the parts housed therein;

Fig. 3 isy a fragmentary view principally in section taken on the line 3 3 of Fig. 2;

Fig. 4 is View partly in elevation and partly in section taken on the line 4 4 of Fig. 2;

Fig. 5 is a view principally in section taken on the line 5 5 of Fig. 1;

Fig. 6 is a view principally in section taken on the line 6 6 of Fig. l;

Fig. '7 is a AView partly in side elevation and partly in section taken on the line I I of Fig. 2;

Fig. 8 is a view corresponding to Fig. 7, but on an enlarged scale, in more complete section and further showing additional associated parts;

Fig. 9 is a fragmentary detail view principally in section taken on the line 9 9 of Fig. 8;

Fig. l0 is a view principally in section taken on the line |ll |l` of Fig. 8;

Fig. 11 is a View corresponding to Fig. 10`but showing the nut and cage in different positions;

Fig. 12 is a perspective view of the nut operating gear removed from the machine; and

Fig. 13fis a perspective view of the nut removed from its operating gear.

The improved machine, as shown in the drawings, is mounted on the cylinder blockV of an internal combustion engine and indicated, as an entirety, by the numeral I4 with the exception of the bores I5.

The improved boring machine includes `a cutter head, indicated as an entirety by the numeral IB, with the exception of its radially movable cutting tool II vand its radially movable centering members I8. This cutter head I6 is rigidly secured to the lower end of a hollow boring spindle or bar I9 in axial alignment therewith and for compound axial and rotary movements through one of the bores I5. Axial movement is imparted to the cutter head I6 by a hollow feed bar 20 through which the boring bar I9 loosely extends in axial alignment therewith. Upper and lower roller bearings 2| and 22 are interposed between the boring bar I9 and feed bar 20 at their upper and lower end portions, respectively, and hold said bars in axial alignment and support' the boring bar I9 for rotary movement in said feed bar. The upper roller bearing 2| is held agaii'ist axial movement on the boring bar |9 between a lower shoulder 23 on said bar and a spur gear 24 keyed to the boring bar I9.

It will be noted that the upper portion of the roller bearing 2| rests on the upper end of 'the feed bar 20 and the spur gear 24 rests on the roller bearing 2| and overlaps said upper end of the feed bar 20. Obviously the roller bearings 2| and 22 and the spur gear 24 connect the boring bar I9 and the feed bar 20 for common axial movement therewith. The spur gear 24 is held against relative axial movement on the boring bar I9 by the roller bearing 2| and a lock-nut 25 that has screw-threaded engagement with said bar above the spur gear 24.

The feed barV 20 ispmounted in a long upright bearing sleeve 26 with freedom for axial sliding movement and which bearing sleeve is integral with a cast base 2l. This base 2'I is adaptedto rest on the flat upper surface of the cylinder block I4 and supports the bearing sleeve 26 with the coincident 'axes of the boring bar I9, the feed bar 20, and the bearing sleeve 26 perpendicular to the top of said block. Y

' Formed with the base 2'I on each side thereof is a hand-piece or lug 28 and above said lug is a hand-hold 29. The top of the base 21 is flat and parallel to the bottom thereof and affords a motor support 30. The bearing sleeve 26 is liigitudinally divided at 3| to permit circumferential contraction of said bearing sleeve onto the feed bar 2li to compensate for wear. Formed with the bearing sleeve 26, on each side of its division 3|, is an outturned flange 32 and a plurality of draw-screws 33 that connect the two flanges 32 and are operable to contract the bearing sleeve 26 onto the feed bar 26.

The feed bar 20 may be manually operated,

5 to raise or lower the cutter head I6, by a handcrank 34, normally loose on a short shaft 35, to

which is rigidly secured a spur pinion 36 that meshes with a long rack 31 on said feed bar. A

simple clutch 38 is provided for temporarily con- 10 necting the hand-crank 34 to the shaft 35, at

will, and comprises a diametrically extended groove in the outer end of the hub of said crank and a fixed transverse pin in the shaft 35. This clutch Vpin is arranged to enter the clutch groove 15 by an axial sliding movement of the hub ofthe hand-crank 34 on the shaft 35. The pinion 36 is mounted in a housing 39, in the form of a boss on the sleeve bearing 26, and the'shaft 3 5 is journaled in said housing. It will be noted thatY a section of the housing 39, in which one end portion'of the shaft 35 is journaled, is removable, as indicated at 40, to afford a passagaway for the pinion 36 when placed in the housing 39 or removed therefrom. A set-screw 4I normally 2.5. holds the housing section 40 in place.

' The bodyY of the rack 31 is mounted in a 1ongitudinauy extended channel in the feed barY 2e and rigidly secured thereto with its teeth extending with clearance into a longitudinally extended -channel 42 in the bearing sleeve 26. The feed b ar 20 is held from turning about its axis in the bearing sleeve 26 by a key plug 31 removably mounted in a seat in said bearing sleeve and held 35k in place by a set-screw 39', see Fig. 6.

` For the purpose of this case, it will not be necessary to illustrate the mechanism in the cutter head for projecting or retracting the centering members I8, except the rotatable operating 40 rod 43 which extends axially and loosely through the tubular boring bar I9. A hand-piece-equipped wheel 44 for the operating rod 43 is applied to the upper end thereof Vand has a depending hub 45V turnably mounted on the upper end of the 45,;boring bar I9. Neither willit be necessary to show the mechanism for prOJ'eClJIlg 0r 1 enacting the cutting tool I 1.

A Thelpinion 24 is driven to rotate the boringY 60 upper-and lower bearings in a housing 5I for the a .g'ears 48-49. This housing 5I has a cover plate 52 removably held in place Yby a plurality of screws. Said housing I is integral, at one end, with the upper end portion of the bearing sleeve 65' 26 and extends horizontally over the motor 46.

v*The armature shaft 41 is also journaled in bear-- ings in the housing 5I and its cover plate 52. The *shaft 50, at its upper end portion, is journaled in bearings in a housing head 53 with free- 70 Adom for said housing to slide thereon.

' Formed with the bottom of the housing head 53, at one end thereof, is a collar. 54 which fits on the. reduced upper end portion of the boring y bar I 9, isv rigidly secured thereto, and extendsV V75jhorizontally over the housing 5I., The housingv head 53 has a cover plate 55 removably held in place by a plurality of screws.

A train of gears in the housing head 53, includ- 4 longitudinally extended keyway 59 in the shaftV The feed bar 26 is automatically moved axially during the rotation of the boring bar I9 to feed the cutter head I6 to its work, by the following connections actuated by they shaft 50. A worm 66, mounted on the shaft 50 in the housing head V53 above the gear 56, is free to slide axially on said shaft but is held for common rotation therewith by the key 58. Mounted on the shaft 56 between the worm 66 and the housing head cover 55 is a roller bearing 66. Meshing with the worm 60 is a worm gear 6I rigidly secured to one end of a short shaft 62 intermediately journaled in a bearing 63 in the housing head 53. A relatively small beveled gear 64 is rigidly se-` cured toI the other end of the shaft 62 and meshes with a relatively largebeveled gear 65 loose on a relatively long fixed feed-screw 66 which extends parallel to the axis of the boring bar I9. The lower end portion of the feed-screw 66 is reduced to form a shank 61 mounted in a bore-like seat in a bearing 68 on the bearing sleeve 26. The feed-screw 66 is held against rotation by a shearing pin 69, see Fig. 8, which extends diametrically through the shank 61 with its end portions anchored in the bearing 68.

The gear 65 is releasably connected to the feedscrew 66 by a novel nut 10 which is longitudinally divided through its center with clearance between the opposing faces-of its sections when in mesh with the feed-screw 66. The sections or elevments of the nut 10 are mounted between a pair of fixed jaws 1I, depending from the hub of the gear 65, and are held thereby for common rotation with said gear but with freedom for movement into or out of mesh with the feed-screw 66. As shown, the curved outer sides of the jaws 1I have the same diameter as the hub on the gear 65 and the inner faces of said jaws are flat and parallel. The opposite sides of the nut 10, which extend between the jaws 1I, are also flat and parallel, as indicated at 12, and have a working t with said jaws which permit the sections of the nut 16 to freely open or close.

A pair of coiled springs 13, mounted in seats in the opposing faces of the sections of the nut 10, are under strain to separate saidsections and move the same out of mesh with the feed-screw 66. The nut 16 is mounted in a cylindrical sleeve-like cage 14 turnably mounted in a cylinder seat in the housing head 53. On the lower end of the cage 14 is an axially aligned hub 15 of reduced diameter and which hub is turnably mounted in a seat therefore in the bottom of the housing head 53. A knurled hand-piece 16, by which the cage 14 may be turned about its axis relative to the nut 10, has an annular flange 11 capping the lower end portion of the hub 15 and thereby holds the hand-piece 16 centered relative to the cage 14. The hand-piece 16 is detachably secured to` the hub 15 by a plurality of screws. 'Ihe feed-screw 66 loosely extends axially through aligned holes in the hand-piece 16 and the hub 15. The cage'. 14 is connected to the gear 65 by a radially Yprojecting .screw-pin 18 anchored to said cage and va circumferentially extended slot 19 in the wall of said cage through which said pin extends. The length of the slot 19 is such as to permit substantially a one-quarter turn of the cage 14 relative to the nut 10.

Formed on the back of each section of the nutI 10 is a cam-acting rib or lug 86 that extends longitudinally thereof midway between the two respective lsurfaces 12. The springs 13 yieldingly hold the sections of the nut 10 at all times with their ribs in bearing contact with the internal surfaces of the cage 14 at diametrically opposite points.

On the internal walls of the cage 14 are diametrically opposite abutment surfaces 8I, which are at the smallest diameter of said cage, and when the cam ribs 86 are in engagement with said ribs the nut 10 is in mesh with the feed-screw 66. When the abutment surfaces 8| are under the ribs 80, as shown in Fig. 9, the pin 18 is in contact with the cage 14, at the forward end of the slot 19, and thereby rotate the cage 14 with the gear 65 and the nut 16 which nut is being moved downwardly on the feed-screw 66. This downward movement of the nut 10 on the feedscrew 66 produces the feeding action to the feed bar 20, which lowers the cutter head I6 in one of the bores I5 and thereby feeds the cutting tool I1 to its work.

Midway between the abutment surfaces 8| at diametrically opposite points, the internal walls of the cage 14 are shaped to form nut-releasing surfaces 8 I and at which surfaces the cage 14 has its greatest diameter. When the sections of the nut 10 are held by the springs 13 with the ribs 86 on the surfaces 8l the nut 16 is out of mesh with the feed-screw 66. From the cage surfaces 8| the internal walls of the cage 14 are shaped to form cam surfaces 82 that lead to the abutment surfaces 8|. When the nut 10 is out of mesh with the feed-screw 66 it is simply rotated by the gear 65 about the axis of said screw.

To release the nut 16 and permit the springs 13 to move the same out of mesh with the feedscrew 66 and thereby stop feeding movement of the feed bar 20, at anytime during boring operation, it is only necessary to grip the hand-piece 16 and turn the cage 14 forward a one-quarter turn relative to the forward turning movement of the nut 10 by the gear 65. The engagement of the cage 14, at the rear end of the slot 19 with the pin 18, limits the forward turning movement of said cage relative to the gear 65 and nut 10 and causes the abutment surfaces 8 I, followed by the cam surfaces 82, to move from under the ribs 86, which are yieldingly held thereon by the springs 13, and position the cage surfaces 8 I back of said ribs. During this movement of the cage 14 relative to the nut 10, said nut has been progressively drawn out of mesh with the feedscrew 66.

To move the sections of the nut 10 into mesh with the feed-screw 66 and thereby start feeding action of the feed bar 20, the hand-piece 16 is gripped and held stationary until the gear 65 has given the nut 10 a one-quarter turn relative to said hand-piece. At the limit of this movement of the nut 10 by the gear 65, the pin 18 will engage the cage 14 at the forward end of the slot 19 and thereby cause the cage 14 to be rotated by the gear 65. While the cage 14 is being held against rotation relative to the rotation of the nut 1U b-y the gear 65, the ribs 80 have been moved by the cam surfaces 82 onto the abutment surmesh'with the feed-screw 66.

A pair of drag devices 83 are provided for yieldingly holding the feed bar 20 in the bearing sleeve 26 against downward slipping movement under the action of the weight of said bar. When the nut 18 is out of mesh with the feed-screw 66 the drag devices 83 also hold the feed bar 20 so that the same is positively moved by the pinion 36 and co-operating rack 31 to give an even feed to the feed bar 20 and prevents the said feed bar from intermittently dropping as the teeth of the pinion 36 move outV of engagement with the teeth of the rack 31. These drag devices 83 are mounted in radial seats in the bearing sleeve 26I equi-distant on each side of a point diametrically opposite the rack 31 and their outer ends are closed by screw plugs.

Each drag device 83 includes a loose metal shoe held in contact with the periphery of the feed bar 2|] by a coiled spring compressed between the respective shoe and screw plug.

For the purpose of this case, it will not be necessary to show the electric circuit for the motor 46, except the movable element 84 of its control switch mounted in a box 85 formed with the housing 5I. The switch element 84 may be manually operated to either start or stop the motor 46. To automatically operate the movable switch element to open the switch and stop the motor 46 at the completion of a boring operation, there is provided a longitudinally adjustable trip rod 86 slidably mounted in a bearing lug 81 above said switch element. This bearing lug 81 is formed with the housing head 53 and the trip rod is held where adjusted by a set-screw 88. This trip rod 86 is arranged to engage and operate the switch element 84, at the completion of a boring operation, to open the switch.

In case the feeding action of thefeed bar 20 isnot stopped either manually ror automatically at the 'completion of a boring operation, the handpiece 16 will engage the bearing 68 and in case of undue strain on the feed-screw 66, the pin 61 will shear and thereby prevent the machine from being damaged. In case the pin 61 does shear the feed-screw 66 will simply rotate with the nut 10.

For the purpose of this case, it is not thought necessary to show the clamp for securing the boring machine to the block I4.

What we claim is:

1. In a boring machine, a feed bar having a fixed head, and means for operating the feed bar including a fixed screw extending through the head, a driven wheel loose on the screw within the head, a two-part longitudinally divided nut connected to the wheel for common rotation therewith but with freedom for axial sliding movement into or out of mesh with the screw, a cage for the nut rotatably mounted in the head, yielding means holding the sections of the nut in engagement with the cage and out of mesh with the screw, said cage having cam surfaces arranged to engage the sections of the nut when out of mesh with the screw by rotating the cage relative to the nut and move said sections into mesh with the screw, a connection for holding the cage for common rotation with the wheel when the nut is in mesh with the screw, said connection having suflicient play to permit the cage to be rotated relativeto the wheel, and a hand-piece on the cage by which it may be held against rotation relative to the wheel or rotated relative thereto.

2. In a boring machine, an upright bearing faces 8I and progressively move the nut V1I] intoV sleeve, a feed bar mounted'in the bearing sleeveVV for endwise sliding movement, a spindle rotatably mounted within the feed bar, a vertical drive shaft, gearing connecting the vertical drive j. shaft and spindle and supported on the upper end of the feed bar, means for operating the feed bar from the vertical drive shaft including a screw and a co-operating nut element, one of which is rotated, said nut element being mounted for movement into or out of mesh with the screw, means for moving the nut element into mesh with the screw, anda spring pressed shoe engaging the feed bar for holding the feed bar against downward sliding movement in the bearing sleeve when the nut element is out of mesh with the screw.

` 3. In a boring machine, a base, an upright bearing sleeve on the base, a tubular feed bar mounted in the bearing sleeve for endwisemovement and having a head, a boring bar journaled in the feed bar, an electric motor mounted on the base with its armature shaft parallel to the feed bar, a driven shaft parallel to the boring bar and journaled in said head, driving connections from the armature shaft to the driven shaft, and other driving connections from the driven shaft to the boring bar including an element mounted on the driven shaft for axial sliding movement, a gear driven wheel loosely mounted on said screw, means for operating the feed bar including a fixed screw, a two part nut element on the screw connected to the wheel for common` rotation therewith but with freedom for radial slid-Y ing movement into or out of mesh with the screw, and cam means surrounding the nut element and connected to the wheel for limited relative turning movement for moving the nut element into and out of mesh with the screw.

4. In a boring machine, a base, an upright bearing sleevel on the base, a tubular feed bar mountedV in the bearing sleeve for endwise movement and having a head overlying the base, a boring bar journaled in the feed bar, an electric motor mounted on the base with its armature shaft parallel to the feed bar, a housing on the bearing sleeve between the base and the head, a driven shaft parallel to the boring bar and journaled in bearings in the head and the housing, driving connections in the housing fro-m the armature shaft to the driven shaft, other driving connections on the head from the driven shaft to the boring bar including an element mounted on the driven shaft for axial sliding movement, means for operating the feed bar including a screw fixed to the housing and extending through the head, a gear driven wheel loosely mounted on said screw, a two part nut element on the screw connected to the wheel for common rotation therewith but with freedom for radial sliding movement into or out of mesh with the screw, and cam means surrounding the nut element and connected to the wheel for limited relative turning movement for moving the nut element into and out of mesh with the screw.

5. In a boring machine, a feed bar having a housing head movable with said bar and means for operating'said bar comprising, a fixed screw exscrew upon rotation of said cage on its mounting in the head relative to said driven member.

6. The structure defined in claim 5,v which further includesa connection from the driven member to the cage for rotating the cage with the'V driven member when the nut element is in mesh with the screw, said connection having sufficient play to permit a limited movement of the cage, in respect to the driven member and in the same direction of rotation, to move the cam means out of engagement with the nut element and permit the nut element to move out of mesh with the screw.

'l'. The structure defined in claim 5, which further includes a slot and pin connection between the driven member and the cage for holding the cage for rotation with the driven member when the nut element is in mesh with the screw, said connection permitting a limited turning movement of the cage relative to the driven member and in the same direction of rotation to move the cam means out of engagement with the nut element and permit the nut element to move out of mesh with the screw.

8. In a boring machine, a feed bar having a housing .head movable with the barrand means for operating said bar comprising, a fixed screw extending through the head of said bar, a bifurcated driven member loose on the screw, a twopart nut mounted for radial sliding movement between the legs of said driven member for rotation therewith, a cage rotatably mounted in said head an-d providing a mounting for said driven member and nut, means connecting said cage and' driven member against relative axial movement but permitting limited rotation of said cage relative to said driven member and nut, spring means holding the sections of said nut in engagement with said cage, and cam means on said cage arranged to engage the sections of said nut to move same into mesh with the screw upon limited rotation of sai-d cage relative to said driven member.

9. The structure defined in claim 8 which fur- 

